This invention relates generally to an exhaust gas duct system for a track-guided vehicle powered by an internal combustion engine and, in particular, to a duct system which extends a short distance above the vehicle roof and into a force-vented exhaust channel arranged alongside the vehicle driving route. A known system is shown in German Published Application DOS No. 3,225,344.
Tunnel routes traveled by track-guided vehicles powered by internal combustion engines can be kept free of gaseous combustion products by a force-vented exhaust channel into which the exhaust gases are introduced. In DOS No. 3,225,344, the disposal of exhaust gases takes place via a fixed part of an exhaust conduit which extends to and terminates at the vehicle roof. A protective pipe surrounds the fixed part of the conduit and conducts air from the engine space which mixes with the exhaust gas in a subsequent, laterally movable part of the exhaust conduit. An open collecting funnel through which ambient air is also taken in covers the ends of the exhaust conduit and of the protective pipe, without being connected to either. The funnel connects to a double-walled transfer pipe having a boat-like cross section which projects between sealing lips into the exhaust channel. Because of the injector effect, exhaust gas is transported into the exhaust channel in spite of the open transition element. The laterally movable part of the exhaust ducting system is mounted by means of fastening stems to the vehicle roof. These stems have hinged joints which form a pivot axis. Righting springs bias the transfer pipe toward a vertical position. A disadvantage of this arrangement is that during startup, or at certain other times, there exists the danger of blowing exhaust gases directly into the interior of the tunnel.
An object of this invention is to provide a system for conducting exhaust gases, as well as air from the engine air space, to an exhaust channel under all operating conditions without restricting the lateral movability of the transfer pipe.
This and other objects are attained in an exhaust duct system which extends from the engine and engine air space vertically to a point above the vehicle roof and into a force-vented exhaust channel located adjacent to the driving route. The duct system comprises an exhaust conduit, a protective pipe surrounding the conduit and terminating a short distance above the vehicle roof, a transfer pipe with a boat-shaped cross-section extending into the exhaust channel, and a gas-tight connecting element for connecting the exhaust conduit and protective pipe to the transfer pipe. The connecting member is pivotable about an axis which extends substantially parallel to a longitudinal axis of the vehicle. In one embodiment, the connecting element comprises an elastic, pleated metal bellows which acts to bias the transfer pipe toward a vertical position. In another embodiment, the connecting element comprises a lower pipe shell attached to the vehicle and the protective pipe and an upper pipe shell attached to the transfer pipe. The upper and lower shells are arranged concentrically around a pivot axis and are sealed at their end faces. A spring is provided in this embodiment for biasing the transfer pipe toward a vertical position.
Further objects, features, and advantages of the present invention will become more apparent from the following description when taken with the accompanying drawings which show, for purposes of illustration only, several embodiments in accordance with the present invention.